Miliband’s citing of Martin Luther King’s “I have a dream” speech in support of his policy of subsidising the construction of many thousands of otherwise uneconomic wind turbines might appear grotesque, even comical; but not if you genuinely believe that Britain’s switching from coal to wind power for its electricity generation will save the lives of countless Africans.

I have no idea whether Miliband truly believes that it will - but if he does, he is deluded. The UK is responsible for less than 2% of global carbon emissions - a figure set to fall sharply, regardless of what we do, as a result of the startlingly rapid industrialisation of countries such as China and India: each year the increase in Chinese CO2 emissions alone is greater than those produced by the entire British economy. On the fashionable assumption that climate change is entirely driven by CO2 emissions, the effect on global temperatures of Britain closing every fossil fuel power station would be much smaller than the statistical margin of error: in effect, zero.

The scientists at the energy and climate change department know this, but their political masters see things differently. [...]

Jeremy Nicholson, the director of the Energy Intensive Users Group, which represents such industries as steel and aluminium, is exasperated beyond measure: "A future administration will have to say in public what ministers and their officials already admit in private, that the renewables target is neither practical nor affordable. Outsourcing our emissions is not a solution to a global problem. Politicians need to understand that unilateral action will come at a terrible cost in terms of UK manufacturing jobs, investment and export revenue, for no discernible environmental gain - is that really what they want?"

It may well be that the English steel mills will become unable to compete globally, even at current domestic energy prices; but deliberately to make them uncompetitive is industrial vandalism - and even madness when the consequence of Miliband’s Martin Luther King moment may be the lights going out not just for producers but for all of us in our homes. This is worse than a futile gesture: it is immoral.

"Anyone who goes around and says that carbon dioxide is responsible for most of the warming of the 20th century hasn't look at the basic numbers."Patrick Michaels - Ph.D. Ecological Climatology, Professor of Environmental Sciences, U. of Virginia

“We have 25 or so years invested in the work. Why should I make the data available to you, when your aim is to try and find something wrong with it.”Phil Jones, Professor in the School of Environmental Sciences at University of East Anglia, to Steve McIntyre